Apparatus for producing grinding wheels



April 20, 1937. w, 5 RAE 2,077,771

APPARATUS FOR PRODUCING GRINDING WHEELS Filed June 16, 1952 5 Sheets-Sheet 1 April 20, 1937.

w. s. RAE 2,077,771

APPARATUS FOR PRODUCING GRINDING WHEELS Filed June 16, 1932 5 Sheets-Sheet 2 April 1937- w. s. RAE 2,077,771

APPARATUS FOR PRODUCING GRINDING WHEELS Filed June 16, 1932 5 Sheets-Sheet 3 Ig 5 Z A?! 67 April 20, 1937. w. s. RAE

FOR PRODUCING GRINDING WHEELS APPARATUS Filed June 16, 1932 5 Sheets-Sheet 4 am/v4. W10

aftcniwus April 20, 1937. w. s. RAE 2,077,771

APPARATUS FOR PRODUCING GRINDING WHEELS A29 /26 /Z M g? w 5%..

Patented Apr. 20, 1937' UNITED- STATES A APPARATUS FOR PRODUCING GRINDING WHEELS Walter S. Rae, Pittsburgh, Pa. Application June 16, 1932, Serial No; 617,681

6 Claims.

Generically this invention relates to machines for winding fibrous material such as thread and the like on suitable cones or cores, but it more especially is directed to the type adapted to simultaneously impregnate the thread and the body being formed, with an abrasive substance durin the winding operation, whereby the production of abrasive bodies such as grindstones and the like are effected.

One of the principal objects of this invention is the provision of a method and apparatus of the above character, including an adjustable pressure means for forming the thread or other fibrous material as it is being wound into the desired shape, and comprising flange elements or disks relatively movable with respect to each other and adapted to be locked in the desired position, whereby the size and shape of the abrasive body or grinding stone may be varied as desired.

An important object of this invention is the provision of means for continuously applying an abrasive substance to the body being formed and the thread as it is wound thereon, and pressure or tamping shoe means for simultaneously forcing the abrasive and impregnated thread into the progressive surface of said body, and maintaining the relative position of said pressure means constant with respect to the surface of said body during its building up process, said tamping means being operable to regulate the degree of hardness and density of said abrasive body as desired.

Another important object of this invention is the provision of a method and apparatus of the above character for producing abrasive bodies such as grindstones and the like, including what may be termed a comb mechanism for directing a strand or a number of strands of fibrous material to the body being formed, and playing such strand or strands from side to side over the surface of such body during its rotative course of being built up, said surface at every stage of the body forming process presenting a woven-like effeet, said mechanism being operable to vary the spaced relation of the respective strands and change the weaving pattern to vary the density of said body by presenting a closely or loosely woven structure as desired, the weaving movement of said mechanism being variable in accordance with differing surface areas of said bodies as desired.

With these and other objects in view, which will become apparent as the description proceeds,

55 the invention resides in the construction, combination, and arrangement of parts, hereinafter more fully described and claimed, and illustrated in the accompanying drawings, in which like characters of reference indicate like parts throughout the several figures, of which:

Fig. 1 is a front elevation of my improved device. r

Fig. 2 is a side view of Fig. 1.

Fig. 3 is a top plan View partly in section taken on the line 3-3 of Fig. 1.

Fig. '4 isa fragmentary detail view partly in section -of the winding and body forming mechanismand operating clutches.

Fig. 5 is a fragmentary detail view of the threader comb operating mechanism.

Fig. 6 is a fragmentary detail view of the adjustable threader comb supporting structure.

Fig. 7 is a section on the line 'I--'l of Fig. 5.

Fig. 8 is a fragmentary detailed transverse section through the pressure mechanism, mounting, and lateral adjusting screw, with the driving screw in elevation.

Fig. 9 is a vertical section on the line 9--9 of Fig. 8.

Fig. 10 is a top plan view of the pressure bar clip.

Fig. 11 is a plan view of the eccentric lock element, and portion of operating handle, and

Fig. 12 is a transverse section of the completed grindstone.

, The devices of this general character with which I am familiar have proven unsatisfactory by being too complex in structure, not readily adjustable to produce different sized abrasive bodies or grindstones, not exerting pressure against the entire surface area of the sides during the building up process, incapable of exerting pressure against the abrasive surface of the body during its building up process, such pressure mechanism receding as the diameter of the body increases,

and likewise incapable of expeditiously changing the weave or spaced relation of the strands of fibrous material wound to form the body, etc., and it was to overcome such deficiencies, and to pro- ,vide a method and apparatus including novel pressure body forming and shaping adjustable disk elements, an adjustable interchangeable shoe pressure mechanism and thread or strand controlling comb mechanism adjustable in accordance with bodies of varying surface areas adapted to direct one or more strands to the device in a manner to maintain the surface of the body level during the winding and building up operation, and capable of changing the spaced relation of said strands and varying the woven-like relation carrying'sprockets I! and I3.

thereof as desired, that I designed the device forming the subject matter of this invention.

In the illustrated embodiment characterizing this invention there is shown a compound fiber and abrasive body forming machine A, adjustable pressure body forming mechanism B, thread control comb mechanism C, and adjustable pressure shoe mechanism D, and which insofar as practicable will be dealt with descriptively under the above headings.

There is shown a supporting frame E comprising in the present instance four perpendicular angle beam standards I connected at their upper ends by cross bars 2 secured thereto by welding or in any suitable manner. Spaced from their lower ends said corner posts or standards are similarly connected by cross bars 3 on which is supported the table top or platform 4 formed with an opening 5 and extending rearwardly beyond standards I and with its free edge supported by angle brace members 6 bolted or otherwise securedthereto and to said standard I. At their lower ends the front standards are similarly connected by cross bars I and similar bars may extend across the ends if desired. The bars I are suitably supported on beams or foot like supports 8 adapted to support the frame structure spaced from the floor as desired.

A substantially rectangular frame section adapted to support the pressure shoe mechanism D and its operating components is positioned adjacent frame E with one side projecting beneath the free edge of platform 4 comprising upright standards 9, connected at their upper ends by side bars I!) and at their lower ends by side bars II and end supporting beams I2 in turn sup ported on bars or feet 8 similar to frame A. One of the side bars I I3 is connected to the platform 4 by brace members I3 bolted or otherwise suitably secured as desired.

Suitably mounted on supporting beams I4 is a power unit or motor [5 having a driving shaft I6 Sprocket I1 is connected by chain I9 passing through opening 5 with sprocket mounted on shaft 2| of the.

speed reducing mechanism 22 (standard type) suitably connected to shaft 23 of the pressure body shaping mechanism now to be described.

Pressure body shaping mechanism The pressure body shaping mechanism B comprises drive shaft 23 mounted at its ends in bearing blocks 24 suitably secured on supporting pedestals 25 supported on beam sections or foot elements 26 similar to elements 8 heretofore described. Said shaft 23 is also mounted in bearing standards 26 suitably secured to the cross beams 3, and spaced inwardly from standard 26 suitably secured to platform 4 are clutch bearing supports 27 and clutch assemblies 28. Secured to platform 4 adjacent supports 21 in any suitable manner are lugs 29 on which are hingedly mounted clutch operating handle elements 30 loosely connected to the complemental slidable clutch members 3I by means of which the driving section 23' of shaft 23 is operatively connected to the end sections of said shaft 23 on which are mounted the cone or core elements 32 on which the thread or fibrous material 33 is adapted to be wound in process of forming the desired body or grindstone F, as will hereafter more fully appear.

' Mounted on said end sections of shaft 23 adjacent the inner edges of the respective'cores (i2 are the pressure disks or plates 34 keyed or suitably looked on said shaft, and mounted, on .5 .46 Shaft adjacent the outer edges of said cores are the similarly shaped complemental disks 35, relatively movable with respect to said disks 34 to accommodate different sized cores 32 according to the desired size of the body F being formed. Said disks 35 are adapted to be locked in the desired adjusted position by lock nut 36 threadedly' mounted on said shaft or other suitable locking means. It is thus apparent that as the thread 33 is wound on the cone or cores 32 and as the body F is built up the disks 34 and 35 will exert pres sure against the sides, shaping the same, and effecting therewith a unitary structure during the building up operation as will directly more fully appear.

Thread control comb mechanism In order to properly direct the thread and the like to the shaping disks 34 and 35, and shiftingly distribute it over the surface of the body being formed on the respective cores 32, I employ the thread control comb mechanism C now to be described.

A plate '5 is attached to the face of each of the front standards 5 by welding or in any other suitable manner at points spaced above the table or platform 4 and of wider dimensions than said standards. A plate 38 is adapted to slidably seat on plate 3! attached thereto by cleat elements secured by screws 49 or in any suitable manner. Said plate is formed at its upper edge with a lateral projection 4| through which extends screw bolt 42 threadedly engageable with lug 43 and squared at its upper end or otherwise formed to engage a suitable wrench for operating said screw to raise and lower said plate 38 as desired.

Secured to the face of plate 38 by bolts 44 spaced from its upper edge are a pair of bearing plates 45 in which is slidably mounted the toothed rack bar 46 formed with a slot 41 engageable with a suitable lug or the like limiting the slidable movement of the bar, and substantially central of the plate adjacent each side secured by bolts 44 is a bearing plate 48 formed with spaced apertured ears or lugs 49 between which is mounted by bolts 44 bearing blocks 50 in which is slidably mounted the thread control toothed rack bar 5| formed with key element 52 engageable in suitable slots in lugs 49 and block 50 to prevent rotation of said bar as will directly more fully appear.

Intermediate said rack bars 46 and M is an arm. 53 welded or suitably secured at one end to plate 33 and having suitably mounted at its free end on bolt 54 idler pinion wheel 55 engageable in the teeth of said rack bars 46 and El. One end of rack bar 5! is rounded as at 56 and suitably secured to the opposite end is arm 5? to the free end of which is suitably secured one end of cable 58 adapted to travel over pulley 59, and to the other end of which is attached counter weight 65 which is adapted to normally maintain rack bar 5| in retracted position. Said pulley 59 is mounted in bracket BI secured by bolts 62 to frame standard I.

The rack bar iii is formed by welding or otherwise adjacent one end with projection 53 terminating in apertured lug B4 to which is adjustably secured by bolt 65 one end of slotted link fit; the other end is similarly secured by bolt 61 to one end of slotted link 68 and to which a similarly slotted link 69 is adjustably secured by bolt "Ill. Link 69 terminates at one end in the thread control comb member ll formed with suitable tines or apertures through which the re- Bill a'owmi:

spectivethreads 33 are directed to thewinding core 32 as-hereinbefore described. The above described link structure permitsadjustment of said combwithrespectto the winding cores 32 5 and-disks- 3i4i and 35 and different si'zed b'odies F formed thereby, as desired;

Positioned intermediate the rack bars 5| and in alignment therewith are the twinshafts I2 mounted at their. outer ends in bearings 13suitably secured andsupported-on, in the'presentin In this connection it is necessary to vary the 5 reciprocal movement of the combs II in accordance with the width of the bodies F being formed and. which is accomplished by eccentrically= ad'- justing the longitudinalaxis of rack bar S-I'With the axis of rotation ofdisk I8. For instance; op-

era-tion of screw 42 in. one direction raises plate 38 oifsetting rackbar 5| with respect to theaxis of rotation of diskJB-andincreases the reciprocating movement of comb 'lI, and the lowering of said plate decreases'said' movement as will be 7 clear without further discussion.

The manner of driving said comb operating mechanism may be described as follows: From sprocket 19 mounted on drive shaft section 23' sprocket chain 80 connecting the same with sprocket wheel 8| suitably secured centrally on shaft 82 journalled in hangers 83-bolted or otherwise secured'to cross beams 84suitably supported by frame members I, and the reduction pulley assemblies 85 securely mounted on shaft 82-. on opposite sides of sprocket BI, and inalignment with their respective complemental assemblies I1 and to which they are adjustably connected by the respective belts 86, as willbei clear without further description.

It might be well before proceeding further'to now describe the mixing units and manner of delivering the abrasive mixture to the respective thread winding mechanisms.

Mounted at the top on .opposite sides of frame E in perpendicular alignment with the cores 32 anddisk assemblies thereon are the abrasive material mixing boxes or containers 8! welded or bolted to frame members 2 and 84, and extending through and suitably journalled in said boxes is said shaft 88 also journalled in spaced bearings 6 89 suitably mounted on-the intermediate cross beams 84 suitably connected. to andsupported by frame E. Keyed or otherwise mountedv on said shaft 88 is sprocket wheel 90in alignment with'sprocket 9| secured on driving section 23' of shaft 23 to which is connected by sprocket chain 92 and by means of which'shaft 88 is'driven to operate the mixing mechanisms mounted in said boxes (not shown"). It will thus be seen that the abrasive material in the boxes 81 is thorough- 1y mixed prior to its delivery through a suitable discharge opening 81 in the bottom thereof to the respective thread Windingcores 32 and body shaping disks 34 and 35 by gravity or through L7 suitable conduits if desired during operation of the machinem process of 'bullding up'the composite fiber and abrasive bodies F. The manner of acting'on the abrasive'material after. it has leftthe boxes B 1 and with respect to the impregnation" of said body therewith by the pressure shoe mechanism D will be now described.

Pressure shoe. mechanism The pressure shoe mechanism D comprises a pair of rectangular bars 93 welded or otherwise suitably secured at their ends to the supporting blocks 94" supported on and-suitably secured'to frame" members I D in approximate alignment with the respective cores 32 and their disks 34 and'351- Mounted on each of the respective bars 93 is=a slidable carrier block-95.1 formed witha cutout opening 96 adapted to receive said bar 93'; 'said opening being closed by screw carrier member 91 securedto said block by screw bolts98'. The carrier member 91 spaced inwardly'from its edges is formed with depending spaced apertured" flanges 99 through which is adapted to extend the driving screw I00 suitably journailed in supporting blocks 94 and terminating as one; end in the shaft member IOI having sprocket wheel I02 mounted on its free end and k'eyedfor otherwise suitably locked thereon.

Mounted on and connecting the free ends of flanges 9'8'is abo-ttom plate I03 secured by bolts llld' thread'edly engageable in said flanges with their heads countersunk as at I95, and mounted on said bottom plate I93 is the eccentric lock member I06 centrally apertured to receive the hub section I07 of lock bolt I98 threadedly en gageablein said plate I93, said lock plate is formedwith operating handle I99 and-with cam slots Il'lll adapted to receive the cam lugs III projecting through openings H2 in said bottom plate and formed on the oomplemental movable locking blocks H3 mounted intermediate flanges 98; Said blocks I-I3 are formed with the complemental hollowed out threaded portions i M adapted'toprovide when the blocks are in looking position threaded engagement with the screw I90 by means of whichblock 95 and its connected parts are caused to slidably traverse bar 93 upon operation of said screw.

Operation of handle I99 causes lugs I I I to move in cam slots III) thereby drawing the complemental locking blocks H3 toward each other andin operative threaded engagement with screw I09 as above described, and movement of said handle in the opposite direction removes said block from contact with said screw permitting carrier block 95 with its connected parts to be P freely slidable withrespect to bar 93, as will be clear; without further explanation.

Carrier block 95 is formed with an opening I I5 communicating with opening H5 in which is adapted to seat the adjusting screw sleeve element II! formed with projection II8 adapted to extend within opening H5, said sleeve adapted to threadedly receive the adjusting screw H9 extending through opening I 29 in carrier block 95.

Dovetail mortiseslot I2I formed in block 95 is adapted to slidably receive the complemental tenon I22 formed on adjusting plate I23, said plate I23 is suitably formed with lugs I24 adapted; toproject in suitable openings I25 formed in the under surface of anchor pressure frame section I26 adapted to seat on said adjusting plate, as will directly more fully appear.

Threadedly anchored in said plate I23 on opaposite sides of pressure anchor bar I21 are the stud bolts I28, and engageable over said pressure anchor frame I26 is a clip plate I29 apertured at one end to receive one of the bolts I28 to which it is rotatably secured by nut I30, and it is formed at its opposite end with curved slot by means of which it is detachably mounted to the opposite bolt I30 thereby firmly maintaining the pressure anchor frame I26 in operative position but permitting its ready removal or the substitution of another interchangeable frame therefor as desired.

Adjacent the outer edge of block 95 adjusting screw H9 is formed with a reduced portion I32 adapted to extend through plate I33 secured to adjusting plate I23 by screws I34. Mounted on said reduced portion I32 is bushing I35, and secured to the free end of said portion in seating engagement with said bushing secured by nut M56 is hand Wheel I31, whereby said screw is rotatably anchored to the adjusting plate I23 and operation of said hand wheel effects adjustment of said frame I26 transversely of bar 93, as will be clear without further description.

Said frame section I23 is substantially triangular in configuration, formed at its supporting corner with a perpendicular section I38 and horizontal section I39 adapted to seatedly engage the adjusting plate I23 as hereinbefore described.

The inclined section I49 of said frame I26 is adapted to form a seat for the substantially triangular shoe pressure bar frame section I4I connected thereto by anchor clip bolts I42, the two frames thus constituting a unitary pressure frame and anchor for the pressure plate member I43. Said plate I43 is adapted to seat on the substantially perpendicular section I44 and is formed at its bottom with lug I45 adapted to engage a suitable opening or recess means not shown suitably connected to frame MI, and is formed at its upper end with lug I46 adapted to seat under catch I41 formed on one end of member I48 hingedly mounted in ears I49, and is formed at its free end with lug I59 having mounted thereon spring II to normally maintain catch I49 in anchoring engagement with pressure plate member I 43. This plate I43 is adapted to be interchangeable with similar plates of different widths corresponding to the width of the particular body F being formed and the space to accommodate such body between the pressure disks 34 and 35 as will be apparent. Likewise in connection with different dimensioned bodies F and, if desirable, at different stages of the building up process, the frame sections MI .and I 25 may be respectively interchangeable with similar frames of different dimensions to adjust and maintain proper relative positions of the bodies F and their pressure disks 34 and 35 with respect to the operatively positioned plate I43, and to coact with the body F during its building up process to form a sumplike space I52 to catch the abrasive material G as it is delivered from the mixing box 81.

Coming now to the driving means and its supporting structure for the operation of screws I90 adapted to cause the respective pressure frames I26--i4l with pressure plates I43 to recede as the diameter of the bodies F increase, the same comprises paralleled beams I53 suitably supported on side bar it with their inner ends extending beneath platform 4 and their outer ends suitably connected to posts I54 welded or otherwise secured to side bar II.

Sprocket chain I55 connects sprocket Wheel I8 on motor shaft I6 with sprocket wheel I56 suit- 75 ably mounted on shaft I51 journalled in bearings I58 suitably secured to platform 4 and beam I53, respectively. Mounted on said shaft I51 spaced from one end is gear wheel I59 adapted to mesh withgear wheel I60 mounted on shaft I 6| journalled in bearings I62 on opposite sides of gear I60 suitably secured to the respective cross bars I63 supportingly connected to beams I53 in any well known manner. Said shaft I6I is operatively connected to the speed reducing unit I 64 suitably mounted on said beams I 53, and with the free end of its shaft I65 carrying sprocket wheels I66 and I61, respectively. Sprocket chain I68 is adapted to connect sprocket I66 with sprocket Wheel I92 mounted on one of the screw shafts II for driving its respective screw I90, and sprocket chain I69 connects sprocket I61 with the other sprocket I02 for driving the remaining screw I60, as will be clear without further description.

Mounted on the top of frame E is the resistor unit I with its control mechanism HI and controller unit I12 with its rheostat I13. By means of these assemblies the speed of the driving motor I5 is determined as will be readily understood.

While the operation of the above described device would seem to be clear, yet it might be well to explain in further detail as to the composition constituting the abrasive mixture G, and the actual impregnation of the body F therewith during process of being formed.

The constituency of the abrasive mixture G may be varied according to the type of abrasive stone or grindstone F desired. The hopper or mixing box 81 mounted above each of the winding assemblies 32-34-35 is adapted to contain a mortar composed of sharp crushed sandstone, flint, emery, or other abrasive, mixed with lime, or cement or other binder, or an abrasive, magnesite, chloride of magnesium and a fluid, such abrasive being delivered to the body F and the thread 33 in course of being wound thereon, and accumulates in the sump-like space I52 inter mediate said body F, flanges or disks 3435 and pressure shoe I43, and at which point it is acted upon by pressure shoe I43 and imbedded in the surface of said body, and in addition to filling the interstices between the threads thoroughly impregnating the threads themselves. The manner of winding the thread, through the instrumentality of the comb mechanisms, from side to side of the body in alternate opposite inclined directions relative to the axis of the body or wheel effects an interwoven fibrous structure impregnated throughout with an abrasive substance under continuous side pressure and surface pressure at right angles thereto, and by virtue of which, a composite abrasive structure or grindstone F is produced.

In conclusion it will be noted that by virtue of the comb mechanism C, threads of different sizes or textures may be directed to the body being formed extending in course of winding from each side, respectively, to approximately the center of the surface of said body to present a variable degree of quality across the thickness so that while one side may be adapted to rapid cutting and in consequence relatively brittle, the other side may have the requisite strength. This also may be effected by the threads or strands of fibrous material being arranged in variable spaced longitudinal relation to the axis of the body, the abrasive substance being applied as hereinbefore described.

In some instances it may be desirable, instead of a single strand or plurality of strands of fibrous material, to use a webbing corresponding to the desired width of the stone to be formed, and in which case the webbing is wound, treated to an abrasive mixture and completed in the same manner as heretofore described.

From the above it will be apparent that I have provided a simple, inexpensive method and apparatus for producing grinding or abrasive bodies from a fibrous material so impregnated with an abrasive and adhesive mixture as to present when the same had hardened a grinding or polishing wheel or grindstone of great durability, constructed at a minimum cost and efficient for the purposes intended.

Although in practice I have found that the form of my invention illustrated in the accompanying drawings and referred to in the above description as the preferred embodiment, is the most efficient and practical; yet realizing the conditions concurrent with the adoption of my invention will necessarily vary, I desire to emphasize that various minor changes in details of construction, proportion and arrangement of parts, may be resorted to within the scope of the appended claims without departing from or sacrificing any of the principles of this invention.

Having thus described my invention, what I desire protected by Letters Patent is as set forth in the following claims:

1. A machine for forming a grindstone body of fibrous material and an abrasive substance, comprising a thread winding mechanism including pressure disks between which the thread is wound to form said body, a comb element for directing the threads to the winding mechanism, a link means adapted to adjustably support the comb With respect to said body, a rack and pinion mechanism adapted to effect reciprocation of the comb with respect-to the winding mechanism, and means for controlling the reciprocatory action of said rack mechanism.

2. A machine for forming a grindstone body of fibrous material and an abrasive substance, comprising a thread winding mechanism including pressure disks between which the thread is wound to form said body, a comb element for directing the threads to the winding mechanism, including a reciprocating bar mechanism, asupporting mechanism carried by said bar adapted to adjustably support the comb with respect to the said winding mechanism, means for reciproeating said bar, means for controlling the reciprocating movement of the bar, and adjustable pressure mechanism adapted to engage said body and maintain a predetermined constant pressure thereon during its building up process, and driving means for effecting simultaneous and positive operation of the thread winding mechanism, bar reciprocating means, and pressure mechanism.

3. A machine for producing a combined polishing and cutting wheel from fibrous material and an abrasive substance comprising a thread winding mechanism including pressure disks, means for delivering the abrasive substance to said winding mechanism, and pressure means for impregnating and embedding the abrasive substance into the thread being wound, said means including a screw driven slidable supporting block, a pressure frame carried by said block, a body engaging pressure plate detachably carried by the frame, means carried by said block movable into and out of threaded engagement with said screw at any point throughout its length, and driving means for efiecting the simultaneous and synchronous operation of the thread winding mechanism and pressure means.

4. A machine for producing a grindstone body from fibrous material and an abrasive substance comprising a thread Winding mechanism including pressure disks, means for delivering the abrasive substance to said winding mechanism, and pressure means including a screw controlled block for impregnating and embedding said substance into the thread being wound, a pressure plate structure carried by said block and adapted to engage said body, means carried by said block normally engageable with the threads of said screw and operable to permit slidable adjustment of the block with respect to the screw, means coacting with said block to effect lateral adjustment of the pressure plate structure with respect to said disks, and driving means for effecting simultaneous and synchronous operation of the,

thread winding and pressure means, whereby a predetermined pressure on said body by the pressure means is maintained constant during its building up process.

5. A machine for producing a grindstone body from fibrous material and an abrasive substance comprising a thread winding mechanism including pressure disks, a comb element for directing the threads to the Winding mechanism, a slidable bar connected to said comb, a rotatable disk coacting with said bar to impart reciprocating movement to the comb, means for delivering the abrasive substance to the Winding mechanism, and pressure means for impregating and embedding the abrasive substance progressively into said body, said pressure means including a screw driven supporting block, a pressure plate supporting structure carried by the block adapted to engage the grindstone body, and driving means adapted to simultaneously and synchronously operate the thread winding mechanism, comb element, and pressure means.

6. A machine for producing a grindstone body from fibrous material and an abrasive substance comprising a thread Winding mechanism including pressure disks, means for delivering the abrasive substance to said winding mechanism, and pressure means for progressively embedding the abrasive substance into the thread being wound, said pressure means including a supporting frame having a detachable pressure plate engageable with said body, a slidable block structure supporting said frame, a driving screw, means carried by said block engageable with the screw and operable to effect longitudinal adjustment of the block with respect to the screw and move said plate into a predetermined pressure engagement with said body, additional means for adjusting said pressure plate laterally with respect to said body, and driving means adapted to simultaneously and positively operate said winding mechanism and pressure means.

WALTER S. RAE. 

